Boiler generating steam according to the indirect method



June 24, 1930; yo. H. HARTMANN 1,768,057

BOILERLGENERATING STEAM ACCORDING T0 THE INDIRECT METHOD Filed Jan. 24. 1928 2 sheets-sheet 1 @K un u :oooovo oo /nuenzor'z June 24, 1930. o. H. HARTMANN 1,768,057

BOILER GENERATING STEAM ACCORDING T0 THE INDIRECT METHOD Filed Jan. 24, 1928 2 Shapts-Sheet 2 Patented June 24, 1930 UNITED STATES PATENT orFrcE or'ro n.. HARTMANN, or cAssELJwILHr-:LMsI-ronn, GERMANY, AssreNon rro scHMIDTscHE nnrssnAMrr-G. B. n., oNlcAssEL-WILHELMsnoHE, GERMANY,

A. CORPORATION OF GERMANY .'BOILER GENERATING STEAM ACCORDING TO THE `IN'DIIRQEGT METHOD` Application filed January 24, 1928, Serial No. 249,120, and in Germany March 17, l1927.

My invention relatesl to boilers generating high-pressure steam according to the indirect method and is designed in particular for those cases in which a boiler installation requires a number of units, in order either-to provide an ample reserve or to meet widelydiering demands at different times.

In boiler installations with boiler units of the usual kind (for example, those with steeply-inclined or slightly-inclined tubes generating steam according yto the direct' method), a complete set of steam drums with their appropriate ttings usually corrsponds to each kfurnace of the battery. The eificiencyl of a boiler installation of this kind falls off, however, at lowV loads, as for example in the type of installation in which the demand for Steam over long periods is only a small fraction of the average demand. In addition, if itis necessary to draw a iire in order to effect repairs to the tube system of the corresponding steam drum or set of steam drums, the entire heating surface associated with the drum or drums concerned, becomes inoperative as regards the generation of steam.

In contrast to the above,rmyfpresent invention makes it possible to work boiler installations at a good eiiciency for-long periods of time at loads below the average; further, if it is necessary to effect repairs to the tube system, a smaller fraction of the heating surface becomes inoperative.

With the objects set forth, my invention consists in a boiler installation of the kind indicated in which the heat-absorbing parts of the tube system serving for the indirect generation of high-pressure steam and corresponding to an individual steam drum, are sub-divided into twoV or more sections separate from one another and arranged respectively in the combustion chambers of a corresponding number of independent furnaces.

In addition, the steam superheater and the preheater commonly provided for the circulating heat-carrier are likewise preferably sub-dividedA into sections corresponding with the number of independent furnaces.

Referring to the accompanying drawings which show one form of the invention by way of example Figure l shows a section of a boiler installation comprising a number of units, .while Figure. 2 shows in section onv the line IIHII of Figure 1 a part of one of the units.

yIn Figure 1, three drums, A, B and C, are shown in which the high-pressure working steam is generatedy according to the, indirect method by means of tube systems, 1, 2, 3, lying in the water spaces of the drums` and vConnected (by connections not shown inFigure 1.) 4to tube systems, 4, 5 and 6, and v7 ,8 and 9, which yare arranged in the combustion chambers of theboilers. v I f 2 and 6 or 7, land so forth, form a numberV of closed circuits in which circulates the heat-carrying' medium, for example water,I

to which heatl from the hot gases is imparted by way yofthe elements, 1, 5,16, 7, andrso forth, whilein the elements, 1, 2 and 3, the heat-carrying mediumy gives Vup its heat to the water in the steam drums, A, B and C. Two furnacesare shown `in association with each steam drum; thus, the furnaces, 10 and 11, correspond to the drum, A, the furnaces, 12 and 13, to drum, B, and the furnaces, 14 and 15, tovdrum, C. Each o-f these furnaces, 10, 11, 12 andl so forth, is independent, that is, it can be brought into or out of operation without affecting the other furnaces. The drum, A, contains the heat-emitting part-s of the tube systems which lie in the combustion chambers lof the two furnaces, 10 and 11, and

so on.

If, therefore, by way of example, only onehalf the qua-nitity of steam is required` from a given -unit over a certain period of working, one of the furnaces (10 for` example) can be put out of operation while the other furnace (11) continues working. In this case only half of the heat-emitting elements, 1,

in the drum, A, generate high-pressure steam,

that is to say, only half as much steam is generated as at full load. y

The circulation tubes passing through each particular furnace are so disposed with ref panied by a continuation of the How of the circulating medium through the tubes in the cold furnace anda corresponding decrease in the e'liiciency of the unit.

Further, in theV casevof replacements or repairs, without interrupting the working of the installation as a whole, the operation of one furnace can be entirely stopped.

i In contrast to the usual forms of boilers, the essential advantage of the present invention lies in the fact that a fraction of the normal quantityofsteam Vcan be generated without the efficiency of the installation suffering. In addition, due to the arrangement l5 offa single working steam drum for several independently-fired tube systems, fewer fittings and accessories are required and consequently the cost of production ofthe improved,boiler'installation is in general reduced. Y 1

A boiler installation according to the present invention is equally suitable for coal, oil or otherfuel. lv Y Ifrdesired, a superh'eater,.16,.and a Vpire- V heater, 17, can be .arranged in theflue of each furnace (see FigurevQ) and connected in the usual manner with the other parts of the boiler, such heaters beingV preferably subdivided into sections to correspond with the ynumber ofindependent furnaces.

, Further, al by-pass, 18, with damper, 19, w may be provided for regulating'the temi Vperature of the'steam inthe superheater, 16. Instead of two independent furnaces, as shown, for each individual steam drum, three or more such furnaces may be provided as desired. w -V Y p Having now particularly described and ascertained the nature'ofmy said .inventionV and 40 in what manner the same is to beperformed,

I declare that Vwhat I claim is Y 1. A boiler installation, comprising in combination, a steam drum, aV plurality ofvfurnaces,'a plurality of sets of tubes in said 4.5 drum, and a set of tubes 4in each of said furnaces disposed belowthe said sets 0f tubes in the drum, each of said sets of furnace tubes being connected with an individual set of the tubes in vthe drum to forma closed system therewith Vfor a circulating heating medium, whereby said drum is adapted to be heated by a plurality of closed systems.

2. A boiler installation according to claim 1, having a superheater for the steam generated, and arpreheater for the circulating medium, the said superheater and preheater being subdivided into sections corresponding to the number of separate furnaces.

In testimony whereof I ax my signature. Y OTTO H. HARTMANN. 

